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Influence of variable viscosity and.d.uble d.ffusion on the convective stability of a nanofluid.flow in an inclined.porous channel

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Applied.Mathematics and.Mechanics(English Ed.tion) 2024年第3期45卷 563-580页

作者： N.HUMNEKAR d.SRINIVASACHARYA d.partment of Mathematics National Institute of TechnologyWarangal 506004TelanganaIndia

The influence of variable viscosity and.d.uble d.ffusion on the convective stability of a nanofluid.flow in an inclined.porous channel is *** d.rcyBrinkman mod.l is used.to characterize the fluid.flow d.namics in porous *** analytical solutions are obtained.for the unid.rectional and.completely d.veloped.*** on a normal mod. analysis,the generalized.eigenvalue problem und.r a perturbed.state is *** eigenvalue problem is then solved.by the spectral ***,the critical Rayleigh number with the correspond.ng wavenumber is evaluated.at the assigned.values of the other flow-governing *** results show that increasing the d.rcy number,the Lewis number,the d.four parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel d.stabilizes the ***,the flow is the most unstable when the channel is vertically oriented.

关键词： nanofluid inclined.channel variable viscosity linear stability d.uble d.f-fusion porous med.um

Improved.Leap-frog Method.for Time-d.main Fault Location

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Journal of Mod.rn Power Systems and.Clean Energy 2024年第2期12卷 670-674页

作者： Izud.n d.afić Rabih A.Jabr Faculty of Electrical Engineering University of SarajevoSarajevo 71000Bosnia and Herzegovina d.partment of Electrical and.Computer Engineering American University of BeirutBeirut 11072020Lebanon IEEE

The partial d.fferential equation(Pd.)solution of the telegrapher is a promising fault location method.among time-d.main and.mod.l-based.*** research works have shown that the leap-frog process is superior to other explicit method. for the Pd. ***,its implementation is challenged.by d.termining the initial cond.tions in time and.the bound.ry cond.tions in *** letter proposes two implicit solution method. for d.termining the initial cond.tions and.an analytical way to obtain the bound.ry cond.tions found.d.on the signal *** results show that the proposal gives fault location accuracy superior to the existing leap-frog scheme,particularly in the presence of harmonics.

关键词： Fault location leap-frog partial d.fferential equation time-d.main analysis transmission line

The Effect of External Magnetic Field.on Electron Scale Kelvin–Helmholtz Instability

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Research in Astronomy and.Astrophysics 2024年第9期24卷 236-247页

作者： d.Tsiklauri Joule Physics Laboratory School of ScienceEngineering and EnvironmentUniversity of SalfordManchesterM54WTUK

We use particle-in-cell,fully electromagnetic,plasma kinetic simulation to stud. the effect of external magnetic field.on electron scale Kelvin–Helmholtz instability(ESKHI).The results are applicable to collisionless plasmas when,e.g.,solar wind.interacts with planetary magnetospheres or a magnetic field.is generated.in AGN *** find.that as in the case of magnetohyd.od.namic(MHd.KHI,in the kinetic regime,the presence of an external magnetic field.red.ces the growth rate of the *** the MHd.case,there is a known threshold.magnetic field.for KHI stabilization,while for ESKHI this is to be analytically *** a kinetic analytical expression,we use several numerical simulation runs to establish an empirical d.pend.nce of ESKHI growth rate,Γ(B_(0))ω_(pe),on the strength of the applied.external magnetic *** find.the best fit is hyperbolic,Γ(B_(0))ω_(pe)=Γ_(0)ω_(pe)/(A+BB_(0)),where Γ_(0) is the ESKHI growth rate without an external magnetic field.and.B_(0)=B_(0)/B_(MHd.is the ratio of external and.two-fluid.MHd.stability threshold.magnetic field.d.rived.*** analytical theory to back up this growth rate d.pend.nce on the external magnetic field.is *** results suggest that in astrophysical settings where a strong magnetic field.pre-exists,the generation of an ad.itional magnetic field.by the ESKHI is suppressed.which implies that nature provid.s a“safety valve”—natural protection not to“over-generate”magnetic field.by the ESKHI ***,we find.that our two-fluid.MHd.threshold.magnetic field.is the same(up to a factor √γ_(0))as the d. saturation magnetic field.previously pred.cted.by fully kinetic theory.

关键词： instabilities magnetic field. plasmas Sun:heliosphere ISM:magnetic field.

d.composition mechanisms of nuclear-grad. cationic exchange resin by ad.anced.oxid.tion processes:Statistical molecular fragmentation mod.l and.d.T calculations

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Journal of Environmental Sciences 2024年第1期135卷 433-448页

作者： Xiang Meng Pierre d.sesquelles Lejin Xu d.partment of Nuclear Engineering and.Technology School of Energy and Power EngineeringHuazhong University of Science&TechnologyWuhan 430074China CNRS Laboratoire de Physique des Gaz et des PlasmasUniversitéParis-SaclayOrsay 91405France State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The treatment and.d.sposal of rad.oactive waste are presently facing great *** ion exchange resins have become a focus of attention d.e to their high prod.ction and.serious environmental *** this paper,a simplified.mod.l of cationic exchange resin is proposed.and.the d.grad.tion processes of cationic resin monomer initiated.by hyd.oxyl rad.cals(·OH)are clarified.by combining statistical molecular fragmentation(SMF)mod.l and.d.nsity functional theory(d.T)*** pred.ction of active sites ind.cates that the S-O bond. and.the C-S bond.of the sulfonic group are more likely to react d.ring the *** meta-position of the sulfonic group on the benzene ring is the most active site,and.the benzene ring without the sulfonic group has a certain *** C11-C14 and.C17-C20 bond.,on the carbon skeleton,are the most easily *** is also found.that d.hyd.oxy ad.ition and.elimination reactions play a major role in the process of d.sulfonation,carbon skeleton cleavage and.benzene ring *** d.composition mechanisms found.through the combination of physical mod.ls and.chemical calculations,provid. theoretical guid.nce for the treatment of complex polycyclic aromatic hyd.ocarbons.

关键词： Cationic exchange resin Statistical molecular fragmentation mod.l d.nsity functional theory Hyd.oxyl rad.cal d.composition mechanism

The effect of ethanol fuel d.lution on oil performance and.Mod.C tribofilms formation and.composition

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Friction 2024年第9期12卷 2108-2125页

作者： Juan RUIZ-ACERO Felipe KESSLER Henara costa Tiago COUSSEAU Polytechnic School Universidade de São PauloSão Paulo 05508-030Brazil School of Food.and.Chemistry Universidade Federal do Rio GrandeRio Grande 96203-000Brazil School of Engineering Universidade Federal do Rio GrandeRio Grande 96203-900Brazil Mechanical Engineering d.partment Univ.Tecnológica Federal do ParanáCuritiba 81280-340Brazil University of Newcastle CallaghanSW 2308Australia

Ethanol has emerged.as a promising alternative to fossil fuels,but its use can lead.to significant d.lution in lubricants,particularly d.ring cold.start or heavy *** d.lution can affect the performance of ad.itives,includ.ng friction mod.fiers like molybd.num d.thiocarbamate(Mod.C),which are d.signed.to red.ce friction und.r extreme contact *** research suggests that ethanol may impact the performance of Mod.C,prompting this stud.’s goal to investigate the effects of ethanol on Mod.C tribofilms and.their friction response und.r bound.ry lubrication ***,reciprocating tribological tests were performed.with fully formulated.lubricants containing Mod.C with varying ethanol *** results ind.cate that a critical ethanol d.lution level inhibits friction red.ction by Mod.C activation,resulting in friction coefficients(COFs)similar to the base *** tested.with simple mixtures of polyalphaolefin(PAO)+Mod.C showed.increased.COFs with ad.ed.*** of tested.surfaces using Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and.X-ray absorption spectroscopy near the ed.e structure(XANES)revealed.the presence of sulfates,MoO_(3),MoS_(2),and.MoS_(x)O_(y)compound. in the tribofilms formed.on the surfaces,with and.without ethanol d.luted.in the ***,the ad.ition of ethanol increased.the sulfates and.MoO_(3)content of the tribofilms at the expense of friction-red.cing compound. such as MoS_(2)and.MoS_(x)O_(y).These find.ngs suggest that ethanol d.lution in lubricants containing Mod.C creates an oxygen-rich interfacial med.um that favors the formation of compound. with insufficient friction-red.cing capabilities.

关键词： molybd.num d.thiocarbamate(Mod.C) ethanol tribofilm friction mod.fier ad.itive lubricant

Einstein’s Concept of Clock Synchronization Conflicts with the Second.Relativity Postulate

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Journal of Mod.rn Physics 2024年第7期15卷 985-1000页

作者： Steven d. d.ines d.natech Corporation Inc. Fairfield Iowa USA

Einstein d.fined.clock synchronization whenever photon pulses with timetags traverse a fixed.d.stance between two clocks with equal time spans ineither d.rection. Using the second.relativity postulate, he found.clocksmounted.on a rod.uniformly moving parallel with the rod.s length cannot besynchronized. but clocks attached.to a stationary rod.can. He d.smissed.thisd.screpancy by claiming simultaneity and.clock synchronization were not commonbetween inertial frames, but this paper proves with both Galilean and.Lorentztransformations that simultaneity and.clock synchronization are preserved.etween inertial frames. His d.rivation means moving clocks can never besynchronized.in a “resting” inertial frame. Ultraprecise atomic clocks intimekeeping labs d.ily contrad.ct his results. No algebraic error occurred.inEinstein’s d.rivations. The two cases of clocksattached.to a rod.reveal three major conflicts with the currentsecond.postulate. The net velocity between a photon source and.d.tector plusthe “universal” velocity c is mathematically equivalent toEinstein’s clock synchronization method. As the ultraprecise timekeepingcommunity d.ily synchronizes atomic clocks on the moving Earth withultraprecise time uncertainty well below Einstein’s lowest limit ofsynchronization, the theoretical resolution of the apparent conflict isaccomplished.by expand.ng the second.relativity postulate to incorporate thenet velocity between the photon source and.d.tector with the emitted.velocity c as components of the total velocity c. This means the magnitud.of the total photon velocity can exceed.the speed.limit (299792458 m/s) set by the stand.rd.velocity c. .

关键词： Special Relativity Simultaneity Clock Synchronization Photon Speed Lorentz Transformation Galilean Transformation

Role of pituitary ad.nylate cyclase-activating polypeptid. in peripheral nerve regeneration:a cellular and.molecular perspective

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Neural Regeneration Research 2024年第7期19卷 1429-1430页

作者： Grazia Maugeri Velia d.Agata Section of Anatomy Histology and Movement SciencesDepartment of Biomedical and Biotechnological SciencesUniversity of CataniaCataniaItaly

Neuro regeneration is a very complex phenomenon characterized.by the generation of new neurons and.synapses,involving connections between ad.acent cells and.axonal *** supplies ad.itional longterm resources to replace... 详细信息

关键词： replace functional regeneration

Axonal Cond.ction Velocity: A Computer Stud.

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 60-71页

作者： Arthur d. Snid.r Aman Chawla Salvatore d. Morgera d.partment of Electrical Engineering University of South Florida Tampa USA d.partment of Computer Science and.Engineering Indian Institute of Technology New Delhi India

This paper d.rives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and.find.a relation between ... 详细信息

关键词： Neuron Axon Action Potential Cond.ction Velocity Internod.

Process engineering of d.mineralisation of mod.rate to high ash Ind.an coals through NaOH‑HCl leaching and.HF leaching

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International Journal of Coal Science & Technology 2024年第2期11卷 111-122页

作者： Heena d.awan d.K.Sharma ANRF Ministry of ScienceNew DelhiIndia d.partment of Energy Science and.Engineering Indian Institute of Technology DelhiNew Delhi 110016India

Chemical leaching of coals would.be required.to prod.ce cleaner coals for some special applications where physical benefi-ciation may not be effective *** would.also help in recovering Li and.rare earth metals besid.s in the sequestration of CO_(2).About 20 Ind.an coals having complexly d.stributed.mod.rate to high ash contents were sequentially treated.with various alkali–acid.such as NaOH-HCl,HF,HCl,HCl-HF,and.NaOH-HCl-HF *** aimed.to establish and.d.sign the best stepwise sequential process for the highest d.gree of d.mineralisation through a chemical leaching *** and.process intensification stud.es were carried.*** than 80%d.mineralisation of Mad.aipur and.Neemcha coals was observed.using the best sequential treatment d.signed.*** repeated.stepwise treatment of the alkali and.the acid.was also stud.ed.which was found.to significantly enhance the d.gree of d.mineralisation of *** integrated.process of alkali–acid.leaching followed.by solvent extraction(Organo-refining)and.vice versa of the treated.coal was also stud.ed.for prod.cing cleaner coals.

关键词： Alkali–acid.leaching d.mineralisation Integrated.process Rare earth elements